Although most attention in integrated circuit manufacturing is presently focused on the steps required to fabricate an integrated circuit chip, the assembly of various components, including the chip, into a package is a commercially significant process. After fabrication of the integrated circuit chip has been completed, the chip must be mounted on an underlying material so that it can be expediently handled as well as electrically contacted. One technique mounts the chip directly on a printed circuit board. A printed circuit board typically is a dielectric material having a metallic pattern on at least one major surface with selected portins of the pattern being electrically contacted to appropriate portions of the chip. Another technique mounts the chip within a plastic package cavity which in turn is mounted on, e.g., a printed circuit mother board. However, both mounting techniques typically use some approach to protect the chip from adverse effects, i.e., to seal the chip from the ambient atmosphere. A ceramic could also be used as the underlying material.
One such approach uses a glob of epoxy over the chip. Another approach uses a plastic cap which is cemented over the chip. Both approaches, unfortunately, have drawbacks. For example, the disadvantages of the epoxy glob include a tendency of the epoxy to spread irregularly over the surface surrounding the chip, i.e., the epoxy flows and neither the direction nor extent of the flow can be precisely controlled. Additionally, as will be readily appreciated, the thickness of the epoxy over the chip cannot be precisely controlled. The use of a plastic cap avoids both of these drawbacks but is, unfortunately, costlier to implement than is the epoxy glob due to the nature of the assembly step required. Additionally, the cap should be leak tested after it is cemented in place to insure that deleterious contaminants will not enter the cap and damage the chip because there is not a tight seal between the cap and the underlying material.